1. Field of the Invention
The present disclosure generally relates to an apparatus for evaluating the effectiveness of insect repellents on human skin using a simulated skin substrate and methods for using same. The method is particularly useful and suitable for testing the efficacy of skin-applied insect repellents and the attraction of biting insects to human subjects without using human testing participants.
2. Description of the Background of the Invention
Insect-transmitted diseases have long been prevalent, however there are significant hurdles to the development of new effective insect repellents because of the difficulties of testing the efficacy of those new repellents. Particularly, the testing of skin-applied insect repellents and the attraction of biting insects to human subjects is difficult to test without using human test subjects.
Efficacy tests without using human subjects have many benefits. In general, tests involving human subjects tend to have higher operational costs and complicated testing protocols. When human subjects are not employed in tests, experimental costs can be reduced significantly. Further, tests using human surrogate apparatuses can be conducted without geographic or environmental limitations. Particularly, similar tests can be conducted in multiple environments, e.g., a temperate or tropical zone, to reduce the number of variables except for those unique to each geographic locale. All of these benefits assist in making improved repellents based on the location of the consumer.
A need exists for human surrogate testing apparatuses and methods for determining the effectiveness of insect repellents. Several previously developed tests involve using a collagen membrane or a piece of fabric over a warmed feeding chamber containing blood, artificial blood, or warm water containing stimulants for insects. However, these tests and methods do not provide comparable testing results to those derived from tests involving human subjects, and collagen-based substrates do not permit repeated testing cycles. Therefore, it is important to develop a human surrogate apparatus and method for testing the effectiveness of insect repellents using a non-collagen based substrate, which provides identical or substantially similar results to tests involving human participants without having the limitations associated with collagen substrates.